How To Fix "NoReverseMatch" in django blog comments? - python

I've tried looking at quite a few posts first, and none of them seem to have an answer to my solution (at least not an obvious one). I'm still very new to Django, so I'm still getting a hang of how everything relates (in terms of the models, views, forms, etc). The blog was originally a carbon-copy of the djangogirls blog from their tutorial, but I wanted to extend it by adding comments from another tutorial on the web. I ran into an error that I couldn't figure out afterwards.
Here's the source code for the comments:
forms.py
class CommentForm(forms.ModelForm):
class Meta:
model = Comment
exclude = ["post"]
views.py
def post_detail(request, pk):
post = get_object_or_404(Post, pk=pk)
comments = Comment.objects.filter(post=post)
d = dict(post=post, comments=comments, form=CommentForm(),
user=request.user)
d.update(csrf(request))
return render_to_response('blog/post_detail.html', d)
def add_comment(request, pk):
"""Add a comment to a post."""
p = request.POST
if p.has_key("body") and p["body"]:
author = "Anonymous"
if p["author"]: author = p["author"]
comment = Comment(post=Post.objects.get(pk=pk))
cf = CommentForm(p, instance=comment)
cf.fields["author"].required = False
comment = cf.save(commit=False)
comment.author = author
comment.save()
return redirect("dbe.blog.views.post_detail", args=[pk])
models.py
class Comment(models.Model):
created_date = models.DateTimeField(auto_now_add=True)
author = models.CharField(max_length=60)
body = models.TextField()
post = models.ForeignKey(Post)
def __unicode__(self):
return unicode("%s: %s" % (self.post, self.body[:60]))
class CommentAdmin(admin.ModelAdmin):
display_fields = ["post", "author", "created_date"]
url pattern (urls.py):
url(r'^add_comment/(\d+)/$', views.post_detail, name='add_comment')
post_detail.html:
<!-- Comments -->
{% if comments %}
<p>Comments:</p>
{% endif %}
{% for comment in comments %}
<div class="comment">
<div class="time">{{ comment.created_date }} | {{ comment.author }}</div>
<div class="body">{{ comment.body|linebreaks }}</div>
</div>
{% endfor %}
<div id="addc">Add a comment</div>
<!-- Comment form -->
<form action="{% url add_comment post.id %}" method="POST">{% csrf_token %}
<div id="cform">
Name: {{ form.author }}
<p>{{ form.body|linebreaks }}</p>
</div>
<div id="submit"><input type="submit" value="Submit"></div>
</form>
{% endblock %}
The error is highlighting this line in post_detail.html:
<form action="{% url add_comment post.id %}" method="POST">{% csrf_token %}
And the error itself says:
NoReverseMatch at /post/1/
Reverse for '' with arguments '(1,)' and keyword arguments '{}' not found. 0 pattern(s) tried: []
And the traceback from django is insanely unwieldy, but it first points back to this line in views.py:
return render_to_response('blog/post_detail.html', d)

If you are using Django newer than 1.4, you need to quote your add_comment:
<form action="{% url 'add_comment' post.id %}" method="POST">

Related

How to update my Django database with a submit button?

I am creating a web application that will serve as a grocery store. The way I set it up is so the customer can come onto the website, click on the items that they would like to purchase, and then click a submit button to purchase those items. The problem I am running into is having a views.py function to take the information of which products were selected and subtracting 1 from the quantity of the database.
"""models.py"""
class Post(models.Model):
title = models.CharField(max_length=100)
Price = models.DecimalField(max_digits=4, decimal_places=2,default=1)
Sale = models.DecimalField(max_digits=4, decimal_places=2,default=1)
quantity = models.IntegerField(default=1)
author = models.ForeignKey(User, on_delete=models.CASCADE)
category = TreeForeignKey('Category',null=True,blank=True, on_delete=models.CASCADE)
def __str__(self):
return self.title
def get_absolute_url(self):
return reverse('post-detail', kwargs={'pk': self.pk})
views.py
class PostListView(ListView):
model = Post
template_name = 'blog/home.html' # <app>/<model>_<viewtype>.html
context_object_name = 'posts'
def inventory(request):
products = request.POST.getlist('products')
for product in products:
a = Post.objects.get(title=product)
a.quantity = a.quantity -1
a.save()
print(products) # This line isn't necessary but it will show what is in your list from the terminal.
return redirect('blog-home')
urls.py
path('user/<str:username>', UserPostListView.as_view(), name='user-posts'),
path('inventory', views.inventory, name='inventory'),
home.html
{% extends "blog/base.html" %}
{% block content %}
<form action="{% url 'inventory' %}" method="POST" id="menuForm">
{% for post in posts %}
{% if post.quantity > 0 %}
<article class="media content-section">
<div class="media-body">
<div class="article-metadata">
<a class="mr-2">{{ post.category }}</a>
</div>
<h2><a class="article-title" >{{ post.title }}</a></h2>
<p class="article-content"> Price: ${{ post.Price }}</p>
<p class="article-content"> Sale: ${{ post.Sale }}</p>
<input type="checkbox" id="product_{{ post.id }}" value="{{ post.title }}" form="menuForm" name="products" > Inventory count: {{ post.quantity }}
</input>
</div>
</article>
{% else %}
{% endif %}
{% endfor %}
<button type="submit" form="menuForm">Confirm Purchase</button>
</form>
{% endblock content %}
My goal is to click on the checkboxes, and when the customer clicks the button on the bottom of home.html, it triggers the inventory function to subtract "1" from the quantity. When I say print(products), then the terminal gives me the title of all the posts that are check-marked. However, it still isn't going into the database and subtracting 1 from the inventory. (I solved it)
Using Post.objects.get('products[x]') does not make sence, the .get(…) method [Django-doc] expects Q objects as positional parameters, or named parameters, so for example:
from django.shortcuts import redirect
def inventory(request):
products = request.POST.getlist('products')
Post.objects.filter(pk__in=products).update(
quantity=F('quantity')-1
)
return redirect('profile')
By using a .update(…) [Django-doc] you decrement all Posts in bulk which is more efficient than making two database queries per Post object.
Using HttpResponseRedirect("{% url 'profile'%}") will not work either. The "{% url 'profile'%}" is just a string, it does not perform any template rendering. Django will normally return a HTTP 302 response, with {% url 'profile' %} as link to go to, but the browser does not understand {% url 'profile' %}, it can only work with a URI.

How to display post and related comments on single page?

I am unable to design a code to render one particular post and it's related comments. The issue is maybe in views.py or the url.
I have looked at multiple sources without any results. I am a novice to coding and feel like I am missing some essential point. Posts and comments are getting created correctly and all comments get the correct post_id assigned.
My models.py is set up like this:
class Post(models.Model):
title = models.CharField(max_length=1000)
content = models.TextField()
date_posted = models.DateTimeField(default=timezone.now)
author = models.ForeignKey(User, on_delete=models.CASCADE)
def __str__(self):
return self.title
def get_absolute_url(self):
return reverse('blog-home')
class Comment(models.Model):
cid = models.AutoField(primary_key=True)
author = models.ForeignKey(User, on_delete=models.CASCADE)
post = models.ForeignKey(Post, on_delete=models.CASCADE)
comment = models.TextField()
comment_date = models.DateTimeField(default=timezone.now)
def save(self, *args, **kwargs):
super(Comment, self).save(*args, **kwargs)
def __str__(self):
return self.comment
def get_absolute_url(self):
return reverse('blog-home')
My views.py is set up like this:
class PostDetailView(DetailView):
model = Post
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
context['comment_list'] = Comment.objects.filter(post=WHAT SHOULD GO HERE?)
return context
I need to pass the Post.id or primary key of the post in the filter above. Can someone explain what it should be?
The url used to access the post detail is as follows:
path('post/<int:pk>/', PostDetailView.as_view(), name='post-detail')
I get the post detail view rendered out as the author, title and content of the post when I have the following in views.py:
class PostDetailView(DetailView):
model = Post
The template for that is as below:
{% extends "blog/base.html" %}
{% block content%}
<article class="media content-section">
<img class="rounded-circle article-img" src="{{object.author.profile.image.url}}">
<div class="media-body">
<div class="article-metadata">
<a class="mr-2" href="{% url 'user-posts' object.author.username %}">{{ object.author }}</a>
<small class="text-muted">{{ object.date_posted|date:"F d, Y P e" }}</small>
{% if object.author == user %}
<div><a class="btn btn-secondary btn-sm m-1 mb-1" href="{% url 'post-update' object.id%}">Update</a>
<a class="btn btn-danger btn-sm m-1 mb-1" href="{% url 'post-delete' object.id%}">Delete</a></div>
{% endif %}
</div>
<h2 class="article-title">{{ object.title }}</h2>
<p class="article-content">{{ object.content }}</p>
</div>
</article>
{% for comment in comment_list %}
<div class='article-content'>
<p>{{comment}}</p>
</div>
{% endfor %}
{% endblock %}
How should I take the post.id or pk of the Post and use it to filter the comments related only to that particular post?
Also, what is a good way to set up a template for rendering the queryset?
You should be able to iterate over the reverse link from Post object to the Comment objects linked to it (by default as comment_set) in your template:
{% for comment in post.comment_set %}
If you want greater control you inject a queryset into the context, something like this, to get the most recent six comments only.
"comments": post.comment_set.order_by("-comment_date")[:6]
The post object selected should be available as self.object in a DetailView and will be default be injected into the render context as object. An invaluable resource for navigating the structure of Django Class-based views is the Classy CBV
site.
Warning: this is "off the top of my head" so don't assume it's all perfect.
A single object will have access to its related objects.
Try this:
class PostDetailView(DetailView):
model = Post
# There's no need to define get_context_data() here
Now your template will have the post available as post (and also object).
All of the comments that have this post are available on the template like this:
{% for comment in post.comment_set.all %}
<div class='article-content'>
<p>{{ comment }}</p>
</div>
{% endfor %}

Django comments not showing in template

I have a system setup to show comments on a post detail page, however the comments are not showing. I have been focusing on the template tags, because I have used this view code elsewhere and it has worked, however I may be wrong. No errors returning, just not showing the comment in the detail view.
userpost_detail.html:
{% extends 'base.html' %}
{% block content %}
<div class="main">
<h1 class="posttitle">{{ userpost.title }}</h1>
<p class="postcontent">{{ userpost.post_body }}</p>
{% if request.user.is_authenticated and request.user == post.author %}
<a class="link" href="{% url 'feed:edit_post' post.id %}">Edit Post</a>
{% endif %}
Add Comment
{% for comment in userpost.usercomment.all %}
{% if user.is_authenticated %}
{{ comment.create_date }}
<!--
<a class="btn btn-warning" href="{% url 'comment_remove' pk=comment.pk %}">
<span class="glyphicon glyphicon-remove"></span>
</a>
-->
<p>{{ comment.comment_body }}</p>
<p>Posted By: {{ comment.author }}</p>
{% endif %}
{% empty %}
<p>No Comments</p>
{% endfor %}
</div>
{% include 'feed/sidebar.html' %}
{% endblock %}
app PostDetailView:
class PostDetailView(DetailView):
model = UserPost
app add_comment_to_post view:
#login_required
def add_comment_to_post(request,pk):
post = get_object_or_404(UserPost,pk=pk)
if request.method == 'POST':
form = CommentForm(request.POST)
if form.is_valid():
comment = form.save(commit=False)
comment.post = post
comment.author = request.user
comment.save()
return redirect('feed:post_detail', pk=post.pk)
else:
form = CommentForm()
return render(request,'feed/comment_form.html',{'form':form})
app urls:
from django.conf.urls import url
from feed import views
app_name = 'feed'
urlpatterns = [
url(r'^new/$',views.CreatePostView.as_view(),name='new_post'),
url(r'^post/(?P<pk>\d+)$',views.PostDetailView.as_view(),name='post_detail'),
url(r'^post/(?P<pk>\d+)/edit/$',views.UpdatePostView.as_view(),name='edit_post'),
url(r'^post/(?P<pk>\d+)/delete/$',views.DeletePostView.as_view(),name='delete_post'),
url(r'^post/(?P<pk>\d+)/comment/$',views.add_comment_to_post,name='add_comment'),
]
Models.py:
from django.db import models
from django.core.urlresolvers import reverse
from django.conf import settings
from django.contrib.auth import get_user_model
User = get_user_model()
# Create your models here.
class UserPost(models.Model):
author = models.ForeignKey(User,related_name='userpost',null=True)
post_date = models.DateTimeField(auto_now_add=True)
title = models.CharField(max_length=150,blank=False)
post_body = models.TextField(max_length=1000,blank=False)
def publish(self):
self.save()
def get_absolute_url(self):
return reverse('index')
def __str__(self):
return self.title
class UserComment(models.Model):
post = models.ForeignKey('feed.UserPost',related_name='comments')
author = models.ForeignKey(User,related_name='usercomment')
comment_date = models.DateTimeField(auto_now_add=True)
comment_body = models.TextField(max_length=500)
def publish(self):
self.save()
def get_absolute_url(self):
return reverse("userpost_list")
def __str__(self):
return self.comment_body
As #user6731765 mentioned you need comments coz of related_name
{% for comment in userpost.comments.all %}
When you get comment_remove error
You need to define a url for comment_remove and define a view for that.
urlpatterns = [
. . . . . .
url(r'^comment/remove/(?P<pk>\d+)/$',views.DeleteCommentView.as_view(),name='comment_remove'),
]
Then in views.py
class DeleteCommentView(DeleteView):
model=UserComment
Due to the related_name you are using for posts in UserComment, try using
{% for comment in userpost.comments.all %}
in your template instead.

Django management form missing or tampered with - management form is in the template

I have a template with lots of forms on it, all wrapped in one form element. I have on MultiForm that is comprised of 4 regular forms, and two formsets. The formsets have been overridden to use custom formset classes.
I render the management forms in the templates, and can see the relevant info in the post.
For the formsets, I initialize the page with only one form visible.
When I try to submit the combined form I get the following error:
ManagementForm data is missing or has been tampered with
I have searched everywhere for the answer, and read about 15 posts on stack overflow with the same error, but none of the solutions seem to help.
The error page highlights the following line:
{{ beneficiaries.management_form }}
Template:
<form class='pension_form' id='implementation_form' action="{% url "confirmation_form" %}" method="post">
{% csrf_token %}
<ul>
{{ the_form.user_info.as_ul }}
</ul>
<ul>
{{ the_form.spouse_info.as_ul }}
</ul>
<div class='formset_container'> {{ children.management_form }}
{% for form in children %}
<div class='formset'><ul>{{ form.as_ul }} </ul><a class="glyphicon glyphicon-plus"></a></div>
{% endfor %}
</div>
<ul>
{{ the_form.employer_info.as_ul }}
</ul>
<ul>
<li>{{ the_form.beneficiary_general.WHO_BENEFITS }}</li>
</ul>
<div id='beneficiary_info_container' style='display:none;'>
<div class='formset_container'>
{{ beneficiaries.management_form }}
{% for form in beneficiaries %}
<div class='formset' >
<ul>{{ form.as_ul }}</ul><a class="glyphicon glyphicon-plus"></a></div>
{% endfor %}
</div>
<ul><li id='inheritance_order'>
{{ the_form.beneficiary_general.BENEFICIARIES_DIE.label_tag }}
{{ the_form.beneficiary_general.BENEFICIARIES_DIE }}
</li>
</ul>
</div>
<button class='btn btn-default main-btn'>{% trans "_Continue" %}
</form>
View:
def show_confirmation_form(request):
ChildFormSet = formset_factory(ChildInfo, formset=ChildInfoFormSet,
extra=14, can_delete=True)
BeneficiaryFormSet = formset_factory(BeneficiaryInfo, formset=BeneficiaryInfoFormSet,
extra=10, can_delete=True)
multi_form_prefix = 'main_form'
child_prefix = 'children_info'
beneficiary_prefix = 'beneficiary_info'
if request.method == 'POST':
form = ConfirmationForm(request.POST, prefix=multi_form_prefix)
children_forms = ChildFormSet(request.POST, prefix=child_prefix)
beneficary_forms = BeneficiaryFormSet(request.POST,
prefix=beneficiary_prefix)
if form.is_valid():
#not ready yet
return HttpResponseRedirect('/thanks/')
else:
form = ConfirmationForm(prefix=multi_form_prefix)
children_forms = ChildFormSet(prefix=child_prefix)
beneficary_forms = BeneficiaryFormSet(prefix=beneficiary_prefix)
context = {'the_form' : form, 'children' : children_forms,
'beneficiaries' : beneficary_forms}
return render(request, "confirmation_form.html", context)
Forms.py
class BeneficiaryInfo(forms.Form):
SHEM_PRATI_MUTAV = forms.CharField(label=_("First_Name"))
SHEM_MISHPACHA_MUTAV = forms.CharField(label=_("Last_Name"))
MISPAR_ZEHUT_MUTAV = forms.IntegerField(label=_("Mispar_Zehut"))
ACHUZ_HALUKA = forms.IntegerField(label=_("Percent_Allocate"))
class BeneficiaryInfoFormSet(BaseFormSet):
def clean(self):
"""
Adds validation to check that no two links have the same anchor or URL
and that all links have both an anchor and URL.
"""
if any(self.errors):
return
teudot_zehut = []
distribution_total = 0
for form in self.forms:
if form.cleaned_data:
teudat_zehut = form.cleaned_data['MISPAR_ZEHUT_MUTAV']
#allow empty forms.
if teudat_zehut:
if teudat_zehut in teudot_zehut:
form.add_error(None, 'No mutavim can share teudot_zehut')
distribution_total += int(form.cleaned_data['ACHUZ_HALUKA'])
if distribution_total != 100:
form.add_error(None, 'Distribution Total must be 100')
In case someone runs into a similar problem:
The problem was the I only showed the formsets if a certain checkbox was checked, and the management form was in the hidden area. I moved it out of the div that was hidden and it worked perfectly.

django - What does this line achieve here?

I'm following a tutorial on effectivedjango.com, and this is the code they have:
views.py:
class CreateContactView(CreateView):
model = Contact
template_name = 'edit_contact.html'
fields = '__all__' #this is needed for error msg Using ModelFormMixin (base class of CreateContactView) without the 'fields' attribute is prohibited.
def get_success_url(self):
return reverse('contacts-list')
def get_context_data(self, **kwargs):
context = super(CreateContactView, self).get_context_data(**kwargs)
context['action'] = reverse('contacts-new')
return context
class UpdateContactView(UpdateView):
model = Contact
template_name = 'edit_contact.html'
fields = '__all__'
def get_success_url(self):
return reverse('contacts-list')
def get_context_data(self, **kwargs):
context = super(UpdateContactView, self).get_context_data(**kwargs)
context['action'] = reverse('contacts-edit', kwargs={'pk' : self.get_object().id})
return context
urls.py:
url(r'^$', contacts.views.ListContactView.as_view(),
name='contacts-list',),
url(r'^new$', contacts.views.CreateContactView.as_view(),
name='contacts-new',),
url(r'^edit/(?P<pk>\d+)/$', contacts.views.UpdateContactView.as_view(),
name='contacts-edit',),
contact_list.html:
{% block content %}
<h1>Contacts</h1>
<ul>
{% for contact in object_list %}
<li class="contact">
{{ contact }}
(edit)
</li>
{% endfor %}
</ul>
Add contact
{% endblock %}
edit_contact.html:
{% block content %}
{% if contact.id %}
<h1>Edit Contact</h1>
{% else %}
<h1>Add Contact</h1>
{% endif %}
<form action="{{ action }}" method="POST">
{% csrf_token %}
<ul>
{{ form.as_ul }}
</ul>
<input id="save_contact" type="submit" value="Save" />
</form>
Back to list
{% if contact.id %}
Delete
{% endif %}
{% endblock %}
Why does the line context['action'] = reverse('contacts-edit', kwargs={'pk' : self.get_object().id}) in views.py look like its calling itself?
What I mean is, this action is called when the submit button is pressed in the contact-edit template, correct? So it starts there, and it is reverse-calling contact-edit which is itself, right?
What am I not seeing here?
Thank you for all your help.
Yes, the line context['action'] = reverse('contacts-edit', kwargs={'pk' : self.get_object().id}) in views.py is calling itself. This line generates the proper url for contacts-edit view.
This is done so that POST requests come to the same view i.e. UpdateContactView which is an UpdateView. There, proper handling will be done i.e. form validation will occur with the sent data. If the form is valid, object will be updated. Otherwise, the form will be displayed again with errors.
Django docs on UpdateView:
A view that displays a form for editing an existing object,
redisplaying the form with validation errors (if there are any) and
saving changes to the object.

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